Electrical regulator



J y 20, 1943- F. J. CHAMPLIN 2,324,322

ELECTRICAL REGULATOR Filed Sept. 12, 1942 Inventor: Franklin J.Champlin,

b W JWAM y His Attovney.

ratented July 20, 1943 ELECTRICAL REGULATOR Franklin J. Champlin,

General Electric Co New York Dalton, Mass., assignor to mpany, acorporation of Application September 12, 1942, Serial No. 458,067

Claims.

This invention relates to electrical regulators and more particularly toimprovements in control circuits for variable ratio transformer typevoltage regulators of the vernier variety.

By vernier variety is meant a dual regulator in which one part providesrelatively coarse steps of voltage correction and another part providesrelatively fine steps or even smooth correction, the latter part havinga maximum range of operation which is of the order of one of the coarsesteps of the first part. A typical example of such a regulator is aso-called step induction voltage regulator. In that regulator aload-ratiocontrol power 'or distribution transformer or a step voltageregulator (usually an auto-transformer) is combined with an inductionvoltage regulator, the two regulators having acommon driving means whichoperates them in such a manner that the induction voltage regulatorprovides an infinite number of intermediate voltages between the tapvoltages or steps of the main regulator. In such a regulator theinduction regulator corresponds to the vernier regulator. When the mainregulator is provided with an auxiliar low voltage winding which is usedto excite the vernier regulator and the vernier regulator in turnexcites a series transformer in the output circuit of the combinedregulator, I have found that it is possible to eliminate the usualpotential transformer used in the automatic control circuits of suchregulators and thereby materially improve their reliability and reducetheir cost.

An object of the invention is to provide a new and improved regulatorsystem.

Another object of the invention is to provide an improved energizingcircuit for the control of variable ratio transformer type voltageregulators.

A further object of the invention is to eliminate the usual potentialtransformer in the control circuit of automatic step induction typeregulators.

The invention will be better understood from the following descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims.

Referring now to the single figure of the drawing, I have shown thereindiagrammatically a preferred embodiment of the invention in the form ofa step induction voltage regulator I. This regulator comprises athree-winding transformer 2 having a multi-tapped primary winding 3, arelatively high voltage secondary winding 4, and a relatively lowvoltage auxiliary winding 5.

tained from a An input circuit 5 of the regulator is connected acrossvarious portions of the winding 3 by means of a ratio adjusting switch 7which selectively makes connection to the tape of the primary winding. Aload or output circuit 8 of the regulator is connected across therelatively high voltage secondary winding 4.

Smooth control of the voltage of the output circuit 8 is obtained bymeans of a vernier regulator shown as an induction voltage regulator 9.This regulator has a primary winding l8 connected across the auxiliarywinding 5 and a secondary winding II connected across the primary orexciting winding it of a series transformer whose secondary winding I3is connected in the output circuit 8.

The induction regulator 9 is constructed in the usual manner whereby itstwo windings are relatively rotatable so as to vary the coupling betweenthem. In this manner the voltage induced in the secondary winding I imay be varied from a maximum to zero in a smooth manner and as thevoltage of this winding is applied across the series transformer asimilarly variable voltage will be inserted in the load circuit inseries with the high voltage secondary winding 4 of the main regulatingtransformer. Consequently, the voltage of the circuit 8 may be variedsmoothly throughout the entire tap range of the main transformer byproperly operating the induction regulator over its range for all thevarious positions of the ratio adjusting switch 1'.

The ratio adjusting switch 1 and the regulator 8 are mechanicallyconnected together by suitable driving means shown schematically as II.This means is operated by any suitable well-known control elementsindicated generally by the control cabinet l5. Such control cabinetscontain a primary electroresponsive device, such as a voltage regulatingrelay or contact-making voltmeter which is actuated in accordance withthe voltage to be regulated or maintained constant by the regulator.Usually this energization is obpotential transformer connected acrossthe output circuit of the regulator.

However, in accordance with the present invention the necessary controlvoltage is obtained from a circuit I 6. One side of this circuit I8 isconnected directly to a point on the auxiliary winding 5 and the otherside of the circuit I6 is connecteddirectly to a point on the excitingwinding H of the series transformer. The circult is completed through adirect interconnection [1 between the two windings l0 and H of theinduction regulator 9.

When this is done cuit, a load-ratio-control regulator connectedtherein, said regulator having a high voltage winding with a fixednumber of effective turns connected across said circuit on the outputside of said regulator, a low voltage auxiliary winding.

on said regulator, a series transformer having its secondary windingconnected in series with said will be of the order of 120 to 240 voltswhich is a suitable regulator control voltage. Consequently, the circuitIt will ordinarily include all of the winding 5. Usually, however, itwill only include a small fraction of the winding i2 because the maximumvoltage of the winding l3 will ordinarily be of the order of of thevoltage of the winding 4 so that the maximum voltage of the winding i2which is included in the control circuit I6 will be of the order of 10%of the voltage of the entire winding H.

The two regulating transformers and the series transformer may all bemounted in the same tank or casing if desired.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications can be made therein without departing from theinvention and, therefore, it is aimed in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In combination, an alternating-current circuit, a variable ratiotransformer type voltage regulator, said regulator having a high voltagewinding with a fixed number of effective turns connected across saidcircuit on the output side of said regulator, a low voltage auxiliarywinding on said regulator, a series transformer having its secondarywinding connected in series with said high voltage winding, adjustablemeans for variably exciting the other winding of said series transformerfrom said auxiliary winding, said means including a directinterconnection between said auxiliary winding and said other winding,and a control circuit for said regulator and adjustable means connectedacross predetermined portions of said auxiliary winding and said otherwinding in series through said direct interconnection.

2. In combination, an alternating-current circuit, a variable ratiotransformer type voltage regulator connected therein, said regulatorcomprising a, main step-by-step regulator and a vernier regulator, saidmain step-by-step regulator having an auxiliary winding for excitingsaid vernier regulator, and an automatic control circuit for saidregulator connected to be energized in accordance with the voltage ofsaid auxiliary winding and a portion of the exciting voltage of saidvernier regulator, the ratio of said two voltages being the same as theratio of the regulating voltages of said main regulating transformer andsaid vernier regulator.

3. In combination, an alternating-current cirhigh voltage winding,adjustable means for variably exciting the other winding of saidseriestransformer from said auxiliary winding, said means including a directinterconnection between said auxiliary winding and said other winding,and a control circuit for said regulator and adjustable means connectedacross predetermined portions of said auxiliary winding and said otherwinding in series through' said .direct'interconnection, the ratio ofthe voltages of said predetermined portions being the same as the ratioof the voltages of said high voltage winding and said secondary winding.

4. In combination, an alternating-current circuit, a variable ratiotransformer type voltage regulator connected therein, said regulatorhaving a high voltage winding with a fixed number.

of effective turns connected across said circuit on the output side ofsaid regulator, a low voltage auxiliary winding on said regulator, aseries transformer having its secondary winding connected in series withsaid high voltage winding, an induction voltage regulator connectedbetween said auxiliary Winding and the other winding of said seriestransformer, a direct interconnection between the windings'of saidinduction voltage regulator, and a control circuit for both of saidregulators connected across predetermined portions of said auxiliarywinding and said other winding of the series transformer in seriesthrough said direct interconnection, the ratio of the voltages of saidpredetermined portions being the same as the ratio of the voltages ofsaid high voltage winding and the secondary winding of said seriestransformer.

5. In combination, a step-induction voltage regulator comprising, incombination, a loadratio-control regulating transformer, an inductionvoltage regulator, said load-ratio-control transformer having a mainrelatively high voltage secondary winding and an auxiliary relativelylow voltage winding, a series transformer having its secondary windingconnected in series with said high voltage winding said seriestransformer having a primary winding connected to be excited from saidauxiliary winding through said induction voltage regulator, a directinterconnection between said auxiliary winding and the primary windingof said series transformer, and a control circuit for said regulatorconnected across predetermined portions of said auxiliary winding andthe primary winding of said series transformer in series through saiddirect interconnection, the ratio of the voltages of said portions ofthe auxiliary winding and the primary winding of the series transformerbeing the same as the ratio of the voltages of said high voltage windingand the secondary winding of said series transformer.

FRANKLIN J. CHAMPLIN.

